Upgrading your existing Drupal 8, 7, and 6 sites is strongly recommended. There are no new features nor non-security-related bug fixes in these releases. For more information about the Drupal 8.0.x release series, consult the Drupal 8 overview. More information on the Drupal 7.x release series can be found in the Drupal 7.0 release announcement, and more information on the Drupal 6.x release series can be found in the Drupal 6.0 release announcement.

Drupal 8 and 7 include the built-in Update Manager module, which informs you about important updates to your modules and themes. Drupal 6 has reached its end of life (EOL) and will not get further updates.